# nviennot/core-to-core-latency

Measures the latency between CPU cores

Repository: https://github.com/nviennot/core-to-core-latency
Canonical: https://ross.abutalabs.com/products/core-to-core-latency
Language: Jupyter Notebook
License: MIT
License Family: permissive
Last push: 2026-03-25T03:26:34+00:00

## Health v2 (maintenance only)
Score: 56/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 74, release rhythm 8, longevity 100
- inputs: {"age_days": 1446, "days_push": 161, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1360, forks 107 (observed 2026-08-28T04:04:29.882910+00:00)

## What it is
A Rust CLI tool that measures the latency of inter-core communication on a CPU by pinning threads to different cores and timing compare-exchange operations through the cache coherence protocol. It publishes a comparison table of median latencies across many modern CPUs.

## Use cases
- measure core-to-core latency on my CPU
- benchmark cache coherence latency between CPU cores
- compare inter-core communication latency across processors
- check NUMA and CCX latency penalties on Ryzen or EPYC
- profile how fast cores can exchange messages via atomics
- evaluate CPU interconnect performance before buying hardware

## When to choose
- you need empirical inter-core latency numbers for performance tuning or hardware evaluation
- you want a simple installable CLI benchmark with published reference results
- you are comparing hybrid, multi-CCX, or multi-socket CPU topologies

## When to avoid
- you need general-purpose CPU benchmarking like throughput or FLOPS
- you want memory bandwidth or single-core performance measurements
- you need a GUI-based system benchmarking suite

## Facets
- artifact type: cli-tool
- maturity: active
- function: benchmarking, cli, developer-tools
- domain: performance, hardware, developer-tools
- platform: windows, cross-platform, cli, rust
- tags: cpu-latency, cache-coherence, microbenchmark, cpu-affinity, rust, command-line, linux, macos

## Member repositories
- nviennot/core-to-core-latency (main) score 56

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:29.882910+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:41:40.141585+00:00, confidence not recorded.
  - readme: https://github.com/nviennot/core-to-core-latency (fetched 2026-08-28T04:04:29.882910+00:00, sha c42178bb3d13)
- Data as of 2026-08-30T08:39:29.467469+00:00.